JPH0125144B2 - - Google Patents
Info
- Publication number
- JPH0125144B2 JPH0125144B2 JP4985481A JP4985481A JPH0125144B2 JP H0125144 B2 JPH0125144 B2 JP H0125144B2 JP 4985481 A JP4985481 A JP 4985481A JP 4985481 A JP4985481 A JP 4985481A JP H0125144 B2 JPH0125144 B2 JP H0125144B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- magnetic recording
- domain
- manufacturing
- recording medium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000005291 magnetic effect Effects 0.000 claims description 34
- 230000005381 magnetic domain Effects 0.000 claims description 27
- 238000004519 manufacturing process Methods 0.000 claims description 14
- 229910017052 cobalt Inorganic materials 0.000 claims description 9
- 239000010941 cobalt Substances 0.000 claims description 9
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000000758 substrate Substances 0.000 claims description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 6
- 239000001301 oxygen Substances 0.000 claims description 6
- 229910052760 oxygen Inorganic materials 0.000 claims description 6
- 239000010408 film Substances 0.000 description 8
- 239000010409 thin film Substances 0.000 description 7
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000007740 vapor deposition Methods 0.000 description 5
- 238000000151 deposition Methods 0.000 description 4
- 230000008021 deposition Effects 0.000 description 4
- 230000005415 magnetization Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 229920006267 polyester film Polymers 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000005294 ferromagnetic effect Effects 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 230000001131 transforming effect Effects 0.000 description 2
- 238000001771 vacuum deposition Methods 0.000 description 2
- 238000007738 vacuum evaporation Methods 0.000 description 2
- 229910000531 Co alloy Inorganic materials 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000007733 ion plating Methods 0.000 description 1
- 239000006247 magnetic powder Substances 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/84—Processes or apparatus specially adapted for manufacturing record carriers
- G11B5/851—Coating a support with a magnetic layer by sputtering
Landscapes
- Magnetic Record Carriers (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
- Thin Magnetic Films (AREA)
Description
【発明の詳細な説明】
本発明は、高密度磁気記録に適した、S/N比
の高い磁気記録媒体の製造法を提供することを目
的とする。DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to provide a method for manufacturing a magnetic recording medium with a high S/N ratio and suitable for high-density magnetic recording.
近年、磁気記録の高密度化を狙つてコバルト系
合金等をメツキ、スパツタ、イオンプレーテイン
グ、真空蒸着等の方法で基板上に形成した金属薄
膜磁気記録媒体が研究されているが、このS/N
特性に関しては、表面性の影響を考察した検討し
かなされておらず、磁性材料に関連したノイズの
解析は全くなされていないため、従来の塗布型媒
体に比べ出力の向上が確認されているにすぎず、
実用性能を決定するS/N比はあまり良くなつて
いないのが現状であつた。 In recent years, with the aim of increasing the density of magnetic recording, research has been conducted on thin metal film magnetic recording media in which cobalt-based alloys are formed on substrates using methods such as plating, sputtering, ion plating, and vacuum evaporation. N
Regarding the characteristics, only the effects of surface properties have been studied, and no analysis of noise related to magnetic materials has been conducted, so it has only been confirmed that the output is improved compared to conventional coated media. figure,
Currently, the S/N ratio, which determines practical performance, has not improved very much.
塗布型磁気記録媒体の場合、S/N改善の指針
はほぼ明確になつており、抗磁力と磁化の強さを
大きくする、表面性を良くする、磁性粉のサイズ
を小さくする、針状比を大きくする、分散性を良
くする、配向性を良くするという方向でS/N改
良がはかられている。 In the case of coated magnetic recording media, the guidelines for improving the S/N are almost clear: increasing the strength of coercive force and magnetization, improving surface properties, reducing the size of magnetic powder, and improving the acicular ratio. Efforts are being made to improve the S/N ratio by increasing the ratio, improving dispersibility, and improving orientation.
一方、金属薄膜媒体の場合、出力向上に関して
は表面粗さを小さくする、抗磁力と磁化の強さを
大きくする、ノイズ低減に関しては表面性を良く
することしかわかつていなかつたし、これらは塗
布型媒体からの類推にすぎない。 On the other hand, in the case of metal thin film media, the only ways to improve output are to reduce the surface roughness, to increase the strength of coercive force and magnetization, and to reduce noise, the only methods known are to improve the surface properties. It is just an analogy from the type medium.
本発明者は多くの実験の結果、コバルトと酸素
を主成分とする金属薄膜磁気記録媒体の消磁磁区
の大きさが、S/Nに本質的に関係していること
を発見した。すなわち、消磁磁区の大きさが、磁
気記録の方向に直角に測定して、0.3μ以下になる
磁性層を用いるとノイズは著しく小さくなり、ま
た、0.03μ以下になると出力が低下するというこ
とに基づくものである。 As a result of many experiments, the inventor of the present invention discovered that the size of the demagnetized magnetic domain of a metal thin film magnetic recording medium whose main components are cobalt and oxygen is essentially related to the S/N. In other words, if a magnetic layer is used in which the size of the demagnetized domain is 0.3μ or less when measured perpendicular to the direction of magnetic recording, the noise will be significantly reduced, and if it is 0.03μ or less, the output will decrease. It is based on
上記の理由はまだ学術的に十分解明されたとは
いいがたいが、本発明者は下記のように推定して
いる。 Although it cannot be said that the above reason has been fully elucidated academically yet, the present inventor estimates as follows.
つまり、金属薄膜媒体の場合、ランダムな消磁
磁区が記録時に周期性の高い記録磁区に変形する
ことにより磁気記録再生が行なわれるが、消磁磁
区が大きいほど記録磁区もまた粗くなるという相
関があるため、磁壁からのランダムな漏洩磁界が
大きくなり、ノイズが増加すると考えられる。逆
に出力については消磁磁区が大きいほど磁性層内
部の強磁性的相互作用が強いことがわかつている
が、このため磁壁の移動度が大きくなり、同じ抗
磁力及び磁化の強さ(直流磁場で測定した値)で
も消磁磁区が大きい方が記録効率が高くなつてい
ると推定される。 In other words, in the case of metal thin film media, magnetic recording and reproduction is performed by transforming random demagnetized magnetic domains into highly periodic recorded magnetic domains during recording, but there is a correlation that the larger the demagnetized magnetic domains, the rougher the recorded magnetic domains. , it is thought that the random leakage magnetic field from the domain wall becomes larger and the noise increases. Conversely, regarding output, it is known that the larger the demagnetized magnetic domain, the stronger the ferromagnetic interaction inside the magnetic layer, but this increases the mobility of the domain wall, and the same coercive force and magnetization strength (in a DC magnetic field) It is estimated that the larger the demagnetized magnetic domain, the higher the recording efficiency (measured value).
本発明は上記に鑑み、真空蒸着法によるコバル
ト系媒体の製造に於て、磁性層から発生する磁性
材料に関連したノイズを解析した結果、S/N比
を飛躍的に改善した媒体を得ることに成功したも
のであり、以下に図面を用い具体的な説明を行
う。 In view of the above, the present invention aims to obtain a medium with dramatically improved S/N ratio as a result of analyzing the noise related to the magnetic material generated from the magnetic layer in the production of cobalt-based media by vacuum evaporation method. This was successfully achieved, and a detailed explanation will be given below using the drawings.
第1図はコバルトと酸素を主成分とする薄膜を
真空蒸着法により基板上に形成した媒体をバルク
イレース(一活消磁)し、ローレンツ法或はビツ
ター法で観察した磁区の模式図である。斜方蒸着
により図のほぼx方向が磁化容易方向となるよう
磁気異方性を有する様に形成し、x方向に磁気記
録を行なう。x方向に直角な方向をy方向とし、
y方向に測定した磁区の幅と、相対出力及び相対
ノイズレベルの関係を測定したデータを第2図に
示す。このときの記録波長は2μであつた。磁区
幅が大きくなるにつれ、出力は上昇し、0.03μ程
度以上でほぼ飽和する。このとき、ノイズレベル
も徐々に上昇するが、磁区幅0.3μ以上で急激に上
昇し、それ以降は磁区幅が2倍になると約4デシ
ベルの割合でノイズが増加する傾向を示す。な
お、試料としては抗磁力が800エルステツドで膜
厚がほぼ1000Åのものを用いたが、本発明者は抗
磁力は400エルステツドから2000エルステツド、
膜厚は200Åから4000Åまでの範囲で確認したが
傾向は全く同じで特異性はなく、媒体の限定要件
は磁区の幅にあることを確認している。 FIG. 1 is a schematic diagram of magnetic domains observed by the Lorentz method or Bitter method after bulk erasing a medium in which a thin film containing cobalt and oxygen as main components was formed on a substrate by vacuum evaporation. It is formed by oblique deposition so that it has magnetic anisotropy so that the direction of easy magnetization is approximately in the x direction in the figure, and magnetic recording is performed in the x direction. The direction perpendicular to the x direction is the y direction,
FIG. 2 shows measured data on the relationship between the width of the magnetic domain measured in the y direction, the relative output, and the relative noise level. The recording wavelength at this time was 2μ. As the magnetic domain width increases, the output increases and almost saturates at about 0.03μ or more. At this time, the noise level also increases gradually, but it increases sharply when the magnetic domain width is 0.3μ or more, and thereafter, when the magnetic domain width is doubled, the noise tends to increase at a rate of about 4 decibels. The sample used had a coercive force of 800 Oersteds and a film thickness of approximately 1000 Å, but the inventors have determined that the coercive force is between 400 Oersteds and 2000 Oersteds.
We confirmed that the film thickness ranged from 200 Å to 4000 Å, but the trends were exactly the same and there was no specificity, confirming that the limiting requirement for the medium is the width of the magnetic domain.
本発明による媒体は第1図の如きランダムなバ
ルクイレース磁区Mが、記録時に周期性の高い記
録磁区に変形することにより磁気記録再生が行な
われるが、磁区が大きいほど磁性層内部の強磁性
的相互作用が強く、そのため磁壁の移動度が大き
く、同じ抗磁力(直流磁場で測定した値)でも記
録効率が高くなり、0.03μ以上で出力が高くなる。
また、磁区が大きいほど磁壁からのランダムな漏
洩磁界が大きくなるため0.3μ以上の磁区幅でノイ
ズが急増していると考えられる。このためバルク
イレースした磁区の大きさが磁気記録の方向に直
角に測定して0.03μから0.3μの範囲のコバルトと
酸素を主成分とする真空蒸着法等による磁性層を
用いるとS/N比が飛躍的に改善された高密度記
録用磁気記録媒体を得ることが可能になつた。 In the medium according to the present invention, magnetic recording and reproduction are performed by transforming random bulk erase magnetic domains M as shown in FIG. 1 into highly periodic recording magnetic domains during recording. The interaction is strong, so the mobility of the domain wall is large, and even with the same coercive force (measured in a DC magnetic field), the recording efficiency is high, and the output is high when the coercive force is 0.03μ or more.
Furthermore, the larger the magnetic domain, the larger the random leakage magnetic field from the domain wall, so it is thought that noise increases rapidly with a domain width of 0.3μ or more. For this reason, when using a magnetic layer made by vacuum evaporation method etc. whose main components are cobalt and oxygen, the size of the bulk erased magnetic domain is in the range of 0.03μ to 0.3μ when measured perpendicular to the direction of magnetic recording, the S/N ratio is It has now become possible to obtain a magnetic recording medium for high-density recording that has been dramatically improved.
なおここで従来法ならびに本発明による磁気記
録媒体の製造法を具体的実験例をもとに説明す
る。 Here, the conventional method and the method of manufacturing a magnetic recording medium according to the present invention will be explained based on specific experimental examples.
実験例 1
厚さ20μmのポリエステルフイルム上に入射角
度0゜、真空度1×10-5Torrで蒸着速度1〜1000
Å/sec、基板温度10℃〜60℃でコバルトを蒸着
した。抗磁力が50〜100エルステツドと小さいた
め、出力も第2図のスケールで−20〜−25dBと
小さいが、ノイズレベルは+20〜+30dBと極め
て高い。この条件下で磁区幅は200μm〜500μmで
あつた。Experimental example 1 Deposition rate 1 to 1000 on a 20 μm thick polyester film at an incident angle of 0°, vacuum level of 1 × 10 -5 Torr
Cobalt was deposited at a substrate temperature of 10°C to 60°C. Since the coercive force is small at 50 to 100 oersteds, the output is also small at -20 to -25 dB on the scale shown in Figure 2, but the noise level is extremely high at +20 to +30 dB. Under this condition, the magnetic domain width was 200 μm to 500 μm.
実験例 2
厚さ20μmのポリエステルフイルム上に入射角
度60゜〜80゜、真空度1×10-5Torr、基板温度10℃
〜60℃、蒸着速度1〜1000Å/secでコバルトを
蒸着した。抗磁力は100〜1000エルステツドで磁
区幅は2μm〜30μmであつた。抗磁力が500エルス
テツド以上のものは出力は0dB近くであつたが、
ノイズは+10〜+15dBと高かつた。Experimental example 2 On a polyester film with a thickness of 20 μm, the incident angle is 60° to 80°, the degree of vacuum is 1 × 10 -5 Torr, and the substrate temperature is 10°C.
Cobalt was deposited at ~60°C and a deposition rate of 1-1000 Å/sec. The coercive force was 100 to 1000 oersted, and the domain width was 2 μm to 30 μm. For those with a coercive force of 500 oersted or more, the output was close to 0 dB, but
Noise was high at +10 to +15dB.
実験例 3
厚さ30μmのポリイミドフイルム上に入射角0゜、
アルゴン分圧1×10-4〜5×10-2Torr、速度1
〜200Å/secでコバルトをDC及び高周波でイオ
ンプレーテイングした。抗磁力が500〜1000エル
ステツドであつたが、磁区が形成されないか或
は、磁区幅が0.03μm以下であつた。ノイズは−
7dB程度であつたが出力が−5〜−6dBであり、
S/Nが悪い。Experimental example 3 An incident angle of 0° on a 30 μm thick polyimide film.
Argon partial pressure 1×10 -4 to 5×10 -2 Torr, speed 1
Cobalt was ion plated with DC and radio frequency at ~200 Å/sec. Although the coercive force was 500 to 1000 oersted, no magnetic domains were formed or the width of the magnetic domains was 0.03 μm or less. The noise is -
It was about 7dB, but the output was -5 to -6dB,
Bad S/N.
以上が従来の製造方法による実験結果である
が、これらの方法では本発明における磁区幅は得
られなかつた。次に本発明者が確立した製造条件
を説明する。 The above are the experimental results using conventional manufacturing methods, but these methods could not obtain the magnetic domain width according to the present invention. Next, the manufacturing conditions established by the present inventor will be explained.
実験例 4
第3図は本発明による磁気記録媒体の製造法で
用いた蒸着装置の模式図であり、1は真空容器、
2は冷却キヤン、3はベースフイルム巻出機、4
は巻取機、5はポリエステルフイルム等のベース
フイルム、6はマスク、7は蒸着材料、8はルツ
ボである。蒸着材料7は電子ビーム等で加熱蒸発
され、ベースフイルム5は冷却キヤン2の周面に
そつて矢印の方向に走行する際、入射角度が90゜
から連続的に低くなり、最小入射角度θまでの範
囲で蒸着される。このとき、ガス導入ノズル9か
ら酸素ガス等を導入し、蒸着膜の諸特性をコント
ロールする。次に第4図は第3図の装置に於て目
的の磁区幅をもつた強磁性薄膜を製造する条件を
解析したデータを示す。横軸に蒸着膜中の酸素濃
度、最小入射角θ、基板温度、蒸着材料としてコ
バルトにニツケルを添加する場合のニツケル濃度
をとり、縦軸にそれらの条件と磁区幅とを関連づ
ける製造フアクタをプロツトしている。磁区幅
は、これらの5つの製造フアクタの積をミクロン
単位で表現した値にほぼ等しくなる。例えば酸素
濃度20%、最小入射角40゜、基板温度60℃、蒸着
速度1000Å/秒、ニツケル濃度20%のとき、製造
フアクタの積は0.37×1.01×1.05×0.6×0.42=
0.1μとなり、高S/N比の磁気記録媒体が得られ
る。Experimental Example 4 FIG. 3 is a schematic diagram of a vapor deposition apparatus used in the method of manufacturing a magnetic recording medium according to the present invention, in which 1 is a vacuum vessel;
2 is a cooling can, 3 is a base film unwinding machine, 4
5 is a winder, 5 is a base film such as a polyester film, 6 is a mask, 7 is a vapor deposition material, and 8 is a crucible. The vapor deposition material 7 is heated and evaporated by an electron beam or the like, and as the base film 5 travels along the circumferential surface of the cooling can 2 in the direction of the arrow, the incident angle decreases continuously from 90° until it reaches the minimum incident angle θ. It is deposited in the range of . At this time, oxygen gas or the like is introduced from the gas introduction nozzle 9 to control various characteristics of the deposited film. Next, FIG. 4 shows data obtained by analyzing the conditions for manufacturing a ferromagnetic thin film having a desired magnetic domain width using the apparatus shown in FIG. The horizontal axis shows the oxygen concentration in the deposited film, the minimum incident angle θ, the substrate temperature, and the nickel concentration when nickel is added to cobalt as the vapor deposition material, and the vertical axis plots the manufacturing factors that relate these conditions to the magnetic domain width. are doing. The domain width is approximately equal to the product of these five manufacturing factors expressed in microns. For example, when the oxygen concentration is 20%, the minimum incident angle is 40°, the substrate temperature is 60°C, the deposition rate is 1000 Å/sec, and the nickel concentration is 20%, the product of manufacturing factors is 0.37 x 1.01 x 1.05 x 0.6 x 0.42 =
0.1μ, and a magnetic recording medium with a high S/N ratio can be obtained.
以上のように、これまでは金属薄膜媒体の場
合、その歴史も浅いため、S/N改善の明解な指
針は得られていなかつたが、本発明により、金属
薄膜媒体特有の現象が発見され、従来にない高
S/Nの媒体が得られるようになつた。 As described above, due to the short history of metal thin film media, clear guidelines for improving S/N have not been obtained, but with the present invention, a phenomenon unique to metal thin film media has been discovered. It has become possible to obtain a medium with an unprecedented high S/N.
第1図は本発明による磁気記録媒体のバルクイ
レース磁区の模式図であり、xは磁気記録方向、
yはそれに直角な方向を示し、第2図は磁気記録
方向に直角に測定したバルクイレース磁区の幅
と、媒体の出力及びノイズ特性の関係を示す図、
第3図は本発明による磁気記録媒体の製造に用い
た蒸着装置の模式図、第4図は第3図に示した装
置に於て本発明における磁区幅を得るための製造
条件要因を解析して示す図である。
FIG. 1 is a schematic diagram of a bulk erase magnetic domain of a magnetic recording medium according to the present invention, where x is the magnetic recording direction,
y indicates the direction perpendicular thereto, and FIG. 2 is a diagram showing the relationship between the width of the bulk erase magnetic domain measured perpendicular to the magnetic recording direction and the output and noise characteristics of the medium.
FIG. 3 is a schematic diagram of a vapor deposition apparatus used to manufacture a magnetic recording medium according to the present invention, and FIG. 4 is an analysis of manufacturing condition factors for obtaining the magnetic domain width according to the present invention in the apparatus shown in FIG. FIG.
Claims (1)
薄膜磁性層を形成する磁気記録媒体の製造法であ
つて、該磁性層の消磁磁区の大きさを、磁気記録
の方向に直角に測定して0.03μから0.3μの範囲と
することを特徴とする磁気記録媒体の製造法。1. A method for manufacturing a magnetic recording medium in which a thin metal magnetic layer containing cobalt and oxygen as main components is formed on a substrate, and the size of the demagnetized magnetic domain of the magnetic layer is measured perpendicular to the direction of magnetic recording. A method for manufacturing a magnetic recording medium, characterized in that the magnetic recording medium has a thickness in the range of 0.03μ to 0.3μ.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4985481A JPS57164421A (en) | 1981-04-01 | 1981-04-01 | Magnetic recording medium |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4985481A JPS57164421A (en) | 1981-04-01 | 1981-04-01 | Magnetic recording medium |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS57164421A JPS57164421A (en) | 1982-10-09 |
JPH0125144B2 true JPH0125144B2 (en) | 1989-05-16 |
Family
ID=12842636
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4985481A Granted JPS57164421A (en) | 1981-04-01 | 1981-04-01 | Magnetic recording medium |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS57164421A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6150218A (en) * | 1984-08-16 | 1986-03-12 | Fuji Photo Film Co Ltd | Production of magnetic recording medium |
-
1981
- 1981-04-01 JP JP4985481A patent/JPS57164421A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS57164421A (en) | 1982-10-09 |
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